Step stool



FIG. 1 is a front elevational view of a step stool showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view, the right side being a mirror image thereof;

FIG. 6 is a cross-sectional view of the tread surfaces of FIG. 2 thereof;

FIG. 7 is a top plan view, of a second embodiment, the difference being in the removal of the diagonal tread strips on each step thereof;

FIG. 8 is a bottom plan view, the difference being in the removal of the rib structure under each step thereof; and,

FIG. 9 is a perspecitve view of the first embodiment of FIGS. 1-5. 

The ornamental design for a step stool, as shown and described. 